I have bought and tested the Polycase Inceptor ARX cartridges in .45 Auto ( ACP )...labeled with the Ruger Brand which pushes a 118 Grain Injection molded "Frangible" bullet screaming at a muzzle velocity of 1307 FPS resulting in 448 FT LBS of energy to the target.
The ARX bullet is frangible on hardened steel and fragmenting against dense bone (akin to a jacket being ripped off of a hollow point that encounters say a femur) and certain intermediate barriers.
The unique arc-shaped grooves in the profile of the ARX are a perfect blend of form and function, and essential to its performance.
These ‘flutes’ act to harness both the rotational and directional energy of the bullet as it impacts a semi-solid target (gelatin, or a deer shoulder, for example).
While the flutes have no effect on the ARX aerodynamically, and thus do not affect accuracy, they grab onto semi-solid or fluid targets to redirect the bullet’s forward energy laterally. This creates the large temporary (wound) cavity and results in the complete transfer of energy to targets that makes this an effective self-defense cartridge.
The ARX is designed to balance the need for damaging penetration with complete transfer of kinetic energy (to ensure the target gets the full blow from the bullet).
This is not about big shallow entry wounds that cause superficial damage...the ARX is designed to cut into and penetrate to a significant wound depth and cause massive hydrostatic shock damage through cavitation along the way.
The ARX creates temporary (wound) cavities that rival other bullets in the same caliber. When the bullet encounters dense bones it fragments, creating multiple wound channels.